Carlos campillo

El bróculi es una hortaliza que en los últimos arios ha presentado un importante incremento en Extremadura, sobre todo en las Vegas Bajas del Guadiana. El destino fundamental era la industria de congelación y deshidratación, pero cada vez en mayor medida se comienza una comercialización del producto fresco. La elección de cultivares resulta complicada, ya que hay gran diversidad de material vegetal y poca información disponible para las condiciones edafoclimáticas de Extre-

Data analysis is often affected by different types of errors as: measurement errors, computation errors, imprecision related to the method adopted for estimating the data. The methods which have been proposed for treating errors in the data, may also be applied to different kinds of data that in real life are of interval type. The uncertainty in the data, which is strictly connected to the above errors, may be treated by considering, rather than a single value for each data, the interval of values in which it may fall: the interval data. The purpose of the present paper is to introduce methods for analyzing the interdependence and dependence among interval-valued variables. Statistical units described by interval-valued variables can be assumed as a special case of Symbolic Object (SO). In Symbolic Data Analysis (SDA), these data are represented as boxes. Accordingly, the purpose of the present work is the extension of the Principal Component Analysis to obtain a visualization of such boxes, on a lower dimensional space. Furthermore, a new method for fitting an interval simple linear regression equation is developed. With difference to other approaches proposed in the literature that work on scalar recoding of the intervals using classical tools of analysis, we make extensively use of the interval algebra tools combined with some optimization techniques.

ABSTRACT A finding by Benzerga et al. (Acta Mater 2001; 49:3071) that the yield strength of Al–7Si–0.3Mg castings is smaller for castings with a fine secondary dendrite arm spacing (SDAS) than for those with a coarse SDAS is revisited. Previous experimental data for Al–Si–Mg castings are reviewed, and new experiments carried out, both on the original castings used in Benzerga et al. and on Al–Si binary alloy castings whose microstructures more closely conform to the theoretical model of Benzerga et al. The experimental results show that the inverse size effect reported by Benzerga et al. was a consequence of different heat-treatments applied to the original castings, rather than to any intrinsic size effect. The present results confirm that there is a negligibly small size effect in both heat-treatable (Al–Si–Mg) and non-heat-treatable (Al–Si) castings.

The synthesis and crystal structure of the microporous crystalline aluminosilicate ERS-10 are here described. The zeolite was synthesized using a 6-azonia-spiro-[5,5]-undecane hydroxide as structure directing agent (SDA), tetraethylorthosilicate (TEOS) and aluminium-isopropoxide (AiP) as silica and aluminum sources, respectively. ERS-10 is characterized by a relatively narrow field of existence, since the unselective SDA used favors the crystallization of other zeolite phases (MTW, MOR, Beta). Crystallization of pure ERS-10 requires the hydrothermal treatment at 443 K for at least 240 h of a gel with the following composition: SiO2/Al2O3 = 80–160, SDA/SiO2 = 0.2–0.3, H2O/SiO2 close to 45. Preliminary low resolution powder X-ray characterization revealed that the material is affected by structural disorder such as stacking faults; however the comparison of the powder pattern, and the analysis of the cell parameters obtained by indexing the sharp reflections, suggested a close correlation among ERS-10 and NU-87 (IZA code NES), EU-1 (IZA code EUO) and nonasil (IZA code NON) type zeolites. Starting from this base, using an extensively model building and the program DIFFaX, we were able to demonstrate that the new zeolite material ERS-10 is an intergrowth of three structurally related zeolite with the NON, EUO and NES framework topology.

Among the abnormalities in erythrocyte porphyrin metabolism already described in patients with chronic renal failure on hemodialysis, a decrease in blood aminolevulinate dehydratase activity has been reported, suggesting the presence in uremic plasma of an inhibitor of the enzyme. The aim of this work has been to isolate and characterize such an inhibitor. Blood samples from 105 patients with chronic uremia were collected; plasma was applied to Sephadex G-100 columns and the fraction with the highest inhibiting capacity was identified and purified by subsequent SDS-polyacrylamide gel electrophoresis, followed by electroelution and electroblotting. It was demonstrated that the factor present in plasma of uremic patients inhibited blood aminolevulinate dehydratase in a concentration-dependent manner; its inhibitory properties were abolished after heat, trypsin and TCA treatment indicating its peptidic nature. The purified inhibitor has an apparent molecular mass of 56.2 kD, it inhibits blood aminolevulinate dehydratase in a competitive way and the Ki value is 12x10(-6) M. The amino acid composition of the inhibitor has been determined and it has been found that its N-terminal amino acid is blocked. The isolated peptide may play a role in heme biosynthesis disturbances and in the pathogenesis of uremic anemia.